This is a bit of a "broken clock is right eventually" sort of thing, though. I could say without any evidentiary basis "there will be a financial crisis" for years and eventually be right, but I don't think it would be fair to say that I predicted it in a meaningful way. The details matter.

I don‘t think so. These predictions were explicit, and were tailored around the economic situations at the time. As you sibling mentions, even some capitalists made the same predictions (or they believed the left-wing economists) and were able to profit off of this.